Fuel feed for diesel-type internal-combustion engines



Jan. 8, I929.

A. C. ATTENDU FUEL FEED FOR DIESEL TYPE INTERNAL COMBUSTION ENGINESFiled Feb 6. 1920 1 AW... Km I I T mw Patented an. :8, 1929.

1mm. c. n'r'rnnnu, or MONTREAL, QUEBEC, CANADA.

Font rn'nn r012. nmsnn'ryrn InrERimL-ooMBusrIoN ENGINES.

' Atacama February 6,1920. Serial 170.356,?74.

v This invention relates to improvements in process of and apparatus forsupplymg fuel oil to Diesel type internal combustlon engines,

and the object of the invention is to provide.

5 for the feeding of oil from a pressure slightly below the air pressureor slightly below the cylinder pressure if the oil is injected d rectly.

' A further object is to provide an 011 feedin "and measuring deviceoperating under on y a slight difference of pressuresbetween intake anddischarge wherebyflexibility and freedom from leakage may be obtainedandsmall parts of .sim le construction employed. ,A still further-o ject isto provide a measuring device which is at every stroke preared todeliver the maximum amount of oil fraction of the oil available fordelivery.

A further object is to provide a device which may be easily andinexpensively manufactured and which-will not readily get out of order.I

he device consists briefly of a small auxiliary' reservoir-on theengine. in which fuel oil ismaintained at a. constant pressure onlyslightly-below the pressureof the. intake a r oriof the cylinderpressure. One or more pumpsare provided in conjunction with thereservoir for feedin oil therefrom into one or more cylinders. 1 n thesuction stroke, the pistons of these pumps move to the llm lt of theirtravel, so as to draw a full char e. On the force-or feedingstroke, thetrave of the pistons may be stopped at any desired point to re ulate theamount of oil delivered. The 011 1s forced into the auxiliaryreservoirby a suitable pump operating proportionatelyto the engine speedand arranged to dehver a greater volume of oil per unit of time than canbe handled by the feed pumps, the surplus oil escaping from thereservoir through an ad-.

'justa'ble relief valve, so that the pressure in the reservoir ismaintained uniform.

In the drawings which illustrate the invention Fig. 1 is a cross sectionon the" line 1- 1,

Figure 2, illustrating one form of device embodying the invention.

tion.

Referring more particularly to the draw.-

ut which may be regulated to deliver any Fig. 2'is avlew partly inlongitudinal secings, 1 1 designates a reservoir capable of sustainlngvery considerable'internal pressures and having heads 12, one not shown,and 13'designates a casing enclosing the operat ng'parts of themeasuring device and having hand-hole plates 14 giving access thereto. Acam shaft or-driving shaft 15 passes through the casing. A pressurepump, designated as a whole by the numeral 16, is provided for supplyingfuel oil to the reservoir '11.- This pump is preferably operated fromthe "shaft 15 and may forconvenience be en- 7 closed in the casing 13.It will be understood,

. however, that this pump maybe entirely separate and located at anysuitable point.

' The pump 16 comprises a body 17 provided with flanges 18 for attachingit'tothe casing 13 and having any suitable number of bores 19'which arepreferably equal in number to the feed pumps which it supplies and whicharea-11in communication with a supply passage 20 to which the suctionpipe 21 connects.

The pump pistons 22 are preferably of the solid plunger type and operateon the feed ing strokes as valves to close oi the bores 19' from'thesupply passage 20, so that the oil is driven out of the bores throughthe check valves .23 into the discharge pipe 24 and thence through thecheck valve 25 into the reservoir 11. The outer end of each piston is .1

preferably provided with a roller :26 running on a cam or eccentric 27fixed to the shaft 15. A spring 28 is arranged between a suitableabutment:29 at the outer end of each piston and the pump body 17. Itwill thus be seen that the pistonsare positively operated by the cams onthe discharge strokes and are operated by the springs on'the suctionstrokes.

The reservoir 11 is provided, with an ad justable relief valve 3 0 ofany suitable design having an overflow p1pe 31 which leads back to amain oil reservoir or to the suction pipe One or more feedin andmeasuring pumps 32 are provided in t e reservoir and each comprises abarrel 33 formed integral with the reservoir or suitably connectedthereto interior of the reservoir. The plunger 35 of each pump projectsbeyond the lower end of the-barrel and 1s provided with a pair of 00-1-having inlet ports 34. communicating with the Y lars 36 and 37,betweenwhich the forked extremi ty of an o erating lever 38 embraces theplunger. The ever 38 is operated by a cam 39 on the shaft 15 'to pressagainst the lower collar 37 and operate the plungerion its suctionstroke and at the same time compress a spring 40 located between thecollar 37 and an adjustable seat41 provided in the casing 13.

The opposite end of the pump is provided with an outwardly-opening checkvalve 42 and communicates with a fuel feed pipe 43 leading to aninjector not shown or other means for deliverin oil into an engine cylf'cinder. It will thus eseen that feed pumps are positively operatedon'th'e suction strokes from the shaft 15 and are operated on the feedstrokes by the springs 40. f

In order to regulate the length of feed strokesand therefore the amountof oil delivered by each pump, a tapered member 45.

is interposed between the reservoir 11 and the collar- 36 of each pump.It is obvious that by shifting this regulator to interpose thicker :orthinner parts thereof between the collar 36 and the reservoir, thestroke oflthelphmger may be regulated;

The feed pumps may be of the fitted plunger type shown or obviously maybe of the being immat erial except as regards simplic- Dating plungertype, the construction ityof manufacture. .7

Theoperation of the device is'as follows The force pump 16, which isoperated by the shaft 15 in -suitable proportion to the speed of theengine, delivers fuel oil to the reservoir I 11 in excess of thecapacityof the feed pumps 32 to withdraw oil from the reservoir, so that thereis alwaysa surplus of oil which escapes through therelief valve and isreturned to the suction sideof, the pressure pump. In this way, a fixedpressure is maintained in the reservolr 11, which bears any desiredrelation to the airsupply pressure or to'the. cylinder pressure ofttheengine according as the valve 30 is adjusted. Preferably, the differenceinpressures is not more than fifteen pounds so that the feed pumps 33are operatin' under very easy conditions and are not su ject to leakage,especially in the check valves 42. As the shaft 15 revolves, the cams 39oscillate the levers 38 to draw the plungers out of the barrels 33, thatis, to operate the plungers during their suction strokes. During thesuction strokes, the valves 42 are closed by backpressurgso that avacuum is drawn in the arrels 33 until the plungers uncover the ports34, whereupon oil from the reservoir;

rushes in and completely fills the ump barrels. During the suctionstrokes, t e springs have been compressed between the collars '37 andabutments41, and, when the cams 39 release the levers 38, these springsdrive the plungers into the barrelsuntil the collars 36 strike theregulators and 1 irelie plunger, movement is thereby stopped. It willthus seen that each barrel is completelyfilled at each suction strokeandfthat, by'adwsting the-regulators, the pumps may dis'char e anythingfrom adrop of oil to the fulldisplacement of each'plunger, Owing .tothecomparatively small-difference inpressures, in the reservoir 11 andengine cy inder, the feed pumpsneed not be 'ofvery strong construc-:tion nor need the springs, 40 be very strong;

In this way, much wear-andtear in the feed 7 and measurlng device iseliminated and accuracy thereby obtained; a

The apparatus shown in the drawings is designed to feed two cylinders,but obviously a single reservoir may contain umpsfor all the cylindersof an engine, '9. though preferably the construction is-arranged asillustated and operatesthose cylinders which. fire consecutivelyin afour cylinder or six cylin ,derengine. Preferably the shaft 15 is gearedto revolve at half the speed of a four-cycle engine or at the full speedof a two-cycle engine. Obviously for large cylinders which I the latterand" with the injector line to provide for theforcible delivery of fuelfrom the chamber int'o'saidinjector line and means for maintaining insaid chamberand throughout the injector :line a supplyof fuel at aconstant normal pressure only slightly below theinjection air orcylinder pressure, said. means comprising a pressure'pump functionin tode 'ver el to the chamber in excess 0 the deliver capacity of themeasuring pum and a functioning to prevent the pressure developed insaid chamberand in'the injector line by means of the pressure pump fromexceeding apredetermined value. g 2.-Fuel"feeding.apparatus for hi hcomve can'iedby the fuel cham er and -pr'ess'ion engines comprising afuel c amber, a measuring pump for delivering fuel from said chambercomprising a cylinder having its inlet connected with-said chamber, aplunger 0 crating in saidcylinder, a lever operative y connected withsaid plunger, a cam shaft, a cam onsaid shaft cooperating with saidlever to operate the plunger in one direction, a spring arranged tooperate the plunger in the opposite direction, an abutment on saidplunger and-?a tapered member adjustably 3 carried by the reservoir andcooperating with said abutment [to plunger under the p uence of saidspring and hiethe stroke ,of the means formaintaining a supply of oil insaid reservoir. i

3. Fuel feeding apparatus as recited in claim 2 in which the lastmentioned means comprising. a pressure pump including a cylinderhaving'its outlet connected to said fuel chamber, a plunger operating insaid cylinder, a spring arranged to operate said plunger on the suctionstroke, and a second cam carried by the aforementioned cam shaft andarranged to operate said plunger on the disl. uel feeding apparatus forhigh com pression engines comprising a fuel chamber, a

measuring pump for delivering oil from said chamber and a pressure pumpfor supplying oil to said chamber in excess of the delivery capacity ofthe measuring pump, each of said pumps including a cylinder having aplunger operating therein, means for placing the fuel. chamber incommunication with the inlet of the measuring chamber and the outlet ofthe pressure pump, a single cam shaft, a pair of cams carried thereby,means controlled by one of said cams for operating the plunger of themeasuring pump in one direction, means controlled by the remaining camfor operating the plunger of the pressure pump in one direction, andindependent means for operating said plungers in the opposite direction.

5. Fuel feeding apparatus for high compression engines comprising acasing formed with an integral fuel chamber located in the upper portionthereof, a measuring pump having its cylinder located in said fuelchamber and communicating therewith, and a punger operating in saidcylinder and projecting below the fuel chamber, a pressure pumpincluding a cylinder located in the casing below the fuel chamber andhaving its outlet connected the casing above the pressure pump, a cam onsaid shaft engageable with the pressure pump plunger to move the samedownwardly, a.

spring arranged to move the plunger of thepressure pump upwardly whensaid plunger is free to so move, a lever extending beneath the cam shaftand pivotally mounted at one end and having the other end engaging theplunger of the measuring pump, a second cam on said cam shaftcooperating with said lever to operate the plunger of the measuring pumpin one direction, and a spring arranged to operate the plunger of themeasuring pump in the opposite direction when the said plunger is freeto so move. a 6. Fuel feeding apparatus for high compression enginescomprising a fuel chamber, a measuring pump including a cylinderarranged in and communicating with said chamber and a plunger operatingin said cylinder and projecting beyond the fuel chamber, means forreciprocating said plunger, a collar fixed to the. projecting portion ofthe plunger, a pair of spaced guides carried by and extendingcircumferentially of the fuel chamber at opposite sides of theprojecting portion of said plunger, a longitudinally tapered membercarried byand slidable between said guides and formed with a centralslot re- V ceiving the plunger therethrough, said mem- .,ber beingengageable with said collar to regulate the effective delivery stroke ofthe plunger.

In witness whereof, I have hereunto set my hand.

ANDRE o. ATTENDU,

